Doubly-fed repulsion motor control system



2 Sheets-Sheet 1 Eyed July 2,- 1945 S. E. NEWHOUSE ETAL DOUBLY-FED REPULSION MOTOR CONTROL SYSTEM quence and seg'uence ifg closes on July 22, 1947.

Normal Power 5e Fe-appl/cafion a/porver'.

i March/or: breax Con/06 y 1947- s. E. NEWHOUSE ETAL 2,424,326

DOUBLY-FED REPULSION MOTOR CONTROL SYSTEM Filed July 2, 1945 2 Sheets-Sheet 2 I II 126 I I I l l l I U I l l INVENTORS 5/mean [Men/b owe ATTORN Y Patented July 22, 1947 UNITED STATES PATENT OFFICE DOUBLY-FED REPULSION MOTOR CONTROL SYSTEM Application July 2, 1945, Serial No. 602,872

Claims.

Our invention relates, generally, to control systems and, more particularly, to systems for controlling the operation of the propelling motors of railway vehicles.

During the operation of railway vehicles which are propelled by alternating current motors of the doubly-fed, repulsion starting type, it is important that the repulsion connections be established when starting from standstill or when reapplying power at low speeds. When reapplying power at medium speeds, the doubly-fed connections must be established instead of the repulsion connections to prevent the motors from flashing-over. When power is reapplied at high speeds, the motors may flash-over even though the doubly-fed connections have been established. A large number of motors have been damaged by flash-overs because the present method of selecting the motor connections for power reapplication permits the repulsion connections to be made at too high a speed and because no means is provided for preventing the operator from restoring power to the motors at high speeds.

An object of our invention, generally stated, is to provide a motor control system which shall be simple and eflicient in operation and which may be economically manufactured and installed.

A more specific object of our invention is to provide anti-flash protection at all speeds of a doubly-fed, repulsion starting motor.

Another object of our invention is to provide for establishing connections for reapplying power to a motor in accordance with the motor speed.

A further object of our invention is to prevent the reapplication of power to a motor above a pretetermined speed.

Another object of our invention is to prevent overspeeding of a motor.

Other objects of our invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of our invention, speed responsive relays and auxiliary relays cooperate to select switches for making the proper connections to reapply power to the motors of a vehicle at low and medium speeds. Reapplication of power is prevented above a predetermined speed and overspeeding of the motors is also prevented by operation of the relays.

For a fuller understanding of the nature and objects of our invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawing, in which:

,Figures 1A and 13, when combined, constitute Al, A2 and A3.

a diagrammatic view of a control system embodying our invention; and

Figures 2 and 3 are charts showing the sequence of operation of part of the apparatus illustrated in Figures 1A and 13.

Referring to the drawing, the system shown therein controls the operation of a pair of traction motors Ill and l l which are of the doubly-fed, repulsion starting type suitable for propelling a railway vehicle (not shown). The motor [0 has an armature winding l2, a main field winding l3 and an auxiliary field winding I4. The motor I I has an armature winding l5, a main field winding it and an auxiliary field Winding l1.

In accordance with the usual practice, the direction of operation of the motors l0 and II is controlled by a reversing switch l8, the operation of which is controlled by a master controller MC which controls the energization of solenoid windings I9 and 20 of a reversing controller RC for operating the reversing switch [8 in a manner Well known in the art. The power for operating the motors I0 and II may be supplied through a. main transformer MT, having a primary winding 2| and a secondary winding 22. The main transformer may be energized through a current collector 23 which engages a trolley conductor 24. The trolley conductor 24 may be energized fromany suitable source of power, such as an alternating current generator system (not shown).

The motors l0 and l I may be connected to the secondary winding 22 of the transformer by means of a switch M and tap-changing switches A preventive coil PC functions in the usual manner to prevent short-circuiting portions of the transformer winding during the tap-changing operations. A switch P is closed during a part of the tap-changing sequence to shunt a portion of the preventive coil from the motor circuit.

Tap-changing switches D2 and D3, which are connected to a reactor 25, are provided for establishing the doubly-fed connections for the motors I0 and I I. A switch S is provided for establishing the repulsion connections when starting from standstill or when reapplying power to the motors at low speeds.

In order to selectively control the operation of the proper switches for reapplying power at low and medium speeds and to prevent the reapplication of power at high speeds, speed responsive relays SR! and SR2 and auxiliary relays ARI, ARZ and ABS are provided. As will be more fully explained hereinafter, these relays also func- 3 tion to prevent overspeeding of the motors I and II.

As shown, the relays SRI and SR2 are of the balanced beam type. The relay SRI has a voltage coil VCI which is connected across the armature winding I5 of the motor II and a current coil CCI which is connected across the field windings I3 and I6. The relay SR2 has a voltage coil VC2 which is connected across the armature winding I2 of the motor I0 and a current coil CCZ which is connected across the field windings I3 and I6. Calibrating resistors 2B, 21, 28 and 29 are provided for the coils VCI, CCI, VC2 and C02, respectively. It will be understood that these relays may be set to operate at any desired speed of the motors by properly adjusting the calibrating resistors.

In accordance with the usual practice, the operation of the switches AI, A2, A3, D2, D3 and S is controlled by a sequence drum SD which is driven by an air engine 3 I. The operation of the air engine 3! is controlled by an on magnet valve 32 and an oif magnet valve 33. The energization of the magnet valve 33 is controlled by a current limit relay LR which is responsive to the current flowing through the auxiliary field windings I 4 and I! of the motors I0 and II. In this manner, the progression of the sequence drum SD is stopped when the current flowing through the relay LR exceeds a predetermined amount.

In order that the functioning of the foregoing apparatus may be more clearly understood, the operation will now be described in more detail. Assuming that it is desired to start the vehicle in a forward direction from standstill, the controller MO is actuated to position I in the forward direction.

At this time, the switches P, AI and M are closed as indicated by the sequence chart in Fig. 2. The energizing circuit for the switch M extends from positive at the controller MC through contact segments 35 and 35, conductor 31, an interlock 38 on the reversing controller RC, conductor 33, contact members 4! of the relay AR2,

conductor 42, the actuating coil of the switch M, conductor 43 and a contact segment 44 of the sequence drum SD to negative. A holding circuit for the switch M is established through an interlock 50.

The energizing circuit for the switch AI may be traced from positive at the controller MC, through contact segments 35 and 45, conductor 43, an interlock 4! on the switch M, conductor 43, contact segments 49 and 5| of the sequence drum SD, conductor 52, the actuating coil of the switch AI, conductor 53 and an interlock 54 on the switch A3 to negative. The energizing circuit for the switch P extends from a contact segment 55 on the sequence drum SD, through conductor 6, the actuating coil of the switch P, an interlock 5'! on the switch A3, conductor 58, an interlock 59 on the switch A2, conductor GI and an interlock 52 on the switch AI to negative.

The closing of the switches AI, P and M connects the motors I 0 and I I across a portion of the secondary winding 22 of the transformer MT through a circuit which extends from the transformer winding 22, through conductor 63, switch AI, conductor 64, switch P, conductor 65, the field windings I 4 and I1, conductor 66, the limit relay LR, conductor 67, reversing switch I8, field windings I6 and I 3, conductor 68, reversing switch I8, conductor 69, the armature windings '4 I5 and I2, conductor II and the switch M to the transformer winding 22.

Following the closing of the switch M, the magnet valves 32 and 33 are energized thereby causing the air engine 3I to operate the sequence drum SD. The energizing circuit for the magnet valve 32 extends from the previously energized conductor 46 through an interlock I2 on the switch M, conductor I3, the actuating coil of the magnet valve 32, conductor I4, and an interlock I5 on the switch M to negative. The energizing circuit for the magnet valve 33 may be traced from the previously energized conductor I3, through an interlock I5 on the switch P, conductor I1, contact segments 18 and 19 on the sequence drum SD, conductor 8I, the actuating coil of the magnet valve 33, conductor 14 and the interlock I5 to negative.

When the sequence drum advances to position I, the switch S is closed to establish the repulsion connections for starting the motors I 0 and II. The energizing circuit for the switch S may be traced from a contact segment 82 on the sequence drum SD, through conductor 83, contact members 84 of the relay ARI, conductor 85, the actuating coil of the switch S, conductor 86 and an interlock 81 on the switch D3 to negative.

When the master controller MC is actuated to position 2, the sequence drum SD is advanced to position 2. The energizing circuit for the magnet valve 32 remains the same a previously traced. The energizing circuit for the magnet valve 33 may be traced from a contact segment 88 on the controller MC through a conductor 39, a segment 3! on the drum SD, conductor 92, an interlock 63 on the switch P, conductor 33, segments and 96 on the drum SD, conductor 97, the contact members of limit relay LR, conductor 92. contact segments 99 and IS on the controller SD, conductor 8 I, the actuating coil of the magnet valve 33 and thence to negative through a cir cuit previously traced.

When the sequence drum is advanced to position 2, the switch A2 is closed and switch P is opened to increase the voltage applied to the motors II] and I I in a manner well known in the art. The energizing circuit for the switch A?! extends from asegment i3I on the drum through conductor I02, the actuating coil of the switch A2, conductor I33 and an interlock 34 on the switch P to negative.

Following the closing of the switch A2, the sequence drum SD is advanced to position 3 to open the switch S and to close the switch D2, thereby establishing the doubly-fed connections for the motors II) and I I in a manner well known in the art. The energizing circuit for the switch D2 extends from a segment I35 on the drum SD through conductor I 35, the actuating coil of the switch D2, conductor I01, an interlock IE8 on the switch D3, conductor I33 and an interlock III on the switch S to negative.

The sequence drum continues to advance under the control of the limit relay LR to position thereby opening switch AI and closing the switch A3 to increase the voltage applied to the motors. The energizing circuit for the switch A3 extends from a segment I I 2 on the drum SD, through conductor II3, an interlock IN on the switch P. the actuating coil of the switch A3, conductor I I5 and an interlock I I E on the switch AI to negative.

It will be noted that the ener izing circuit for the magnet valve 33 was transferred from the interlock 93 on the switch P to an interlock II! on the switch A2 upon closing of the switch A2 and the opening of the switch P. Thus, the energizing circuit was extended from the conductor 92 through the interlock III, conductor H8, 2 segment IIS and thence to the magnet valve 33 through a circuit previously traced. Likewise, the energizing circuit for the magnet valve 33 was transferred from the interlock III to an interlock I2I upon the closing of the switch A3. The energizing circuit now extends from the conductor 92, through the interlock I2 I, conductor 94, a segment I22 on the drum SD and thence to the magnet valve 33 through a circuit previously traced.

Following the closing of the switch A3, the sequence drum advances to position 5, thereby opening the switch D2 and closing the switch D3. The energizing circuit for the switch D3 extends from a segment I23 on the drum SD, through conductor I24, the actuating coil of the switch D3, conductor I08 and the interlock I I I onthe switch S to negative. The closing of the switch D3 applies maximum voltage to the motors and completes the normal power sequence when the vehicle is started from standstill.

The operation of the system will now be de scribed in case power is shut off from the motors by actuating the master controller MC to the oil position, and then reapplied to the motors by actuating the master controller to the running position while the vehicle is still in motion. As explained hereinbeiore, the speed responsive re lays SRI and SR2 cooperate with the relays ARI. ARZ and AR3 to select the proper switch, either S or D3, to establish either the repulsion connections or the doubly-fed connections in accordance with the speed of the vehicle when power is reapplied. As further explained hereinbefore, the relays SRI and SR2 may be adjusted to operate at any desired speed. Thus, it may be assumed that the relay SRI is set at 24 miles per hour and the relay SR2 is set at 55 miles per hour.

If power is reapplied below 24 miles per hour, the switch S is closed to establish the repulsion connections for the motors. Under these con.- ditions, the energizing circuit for the switch S is established through the contact segment 82 on the sequence drum SD and the contact members 84 of the relay ARI as previously explained. Following the closing of the switch S, the sequence drum SD advances to close the switches A2, D2, A3 and D3 in the manner hereinbefore explained and as indicated in the sequence chart shown in Fig. 2.

If power is reapplied at speeds of 24 to 54 miles per hour, the contact members of the relay SRI are closed. The closing of the contact members of the relay SRI energizes the relay ARI, thereby opening the contact members 84 of this relay to prevent the closing of the switch S and cause the switch D3 to be closed when the sequence drum advances to position I. The energizing circut for the relay ARI may be traced from a segment I25 on the drum SD through conductor I26, the contact members of the relay SRI, conductor I21, an interlock I28 on the relay AR3, conductor I29, contact members I3I on the relay ARI, the actuating coil of the relay ARI, conductor I99 and the interlock III on the switch S to negative.

The relay ARI will hold itself in by means of its transfer contact members I32 which are closed before the circuit through the contact members I3I is interrupted. Thus, the actuating coil of the relay ARI is maintained energized from the conductor 48, thereby insuring that the relay closes and remains closed.

The energizing circuit for the switch D3 extends from the conductor 83 through contact members I33, on the relay ARI, conductor I24 and thence through the actuating coil of the switch D3 to negative through a circuit previously traced. In this manner, the switch D3 is closed to establish the doubly-fed connections for the motors which, as explained hereinbefore, is necessary to prevent flashing of the motors when power is reapplied while operating at medium speeds.

If the operator attempts to reapply power at 55 miles per hour or higher, the contact members of both relays SRI and SR2 will close, and both auxiliary relays ARI and AR2 will close. The energizing circuit for the relay AR2 extends from the conductor I26, through the contact members of the relay SR2, conductor I34, contact members I35 of the relay AR2, the actuating coil of the relay AR2 and thence to negative through the conductor I99 and the interlock III on the switch S. The relay AR2 is held closed r by its transfer contact members I36, which transfer the energizing circuit for the coil of the relay to the conductor 39 before the circuit through the contact members I35 is interrupted.

The operation of the relay AR2 opens the cir- .cuit through its contact members 4|, thereby interrupting the energizing circuit for the switch M. The opening of the switch M will break the circuit through its interlock 41 thereby deenergizing the conductor 48 and the contact segment 49 of the sequence drum which will prevent the switch D3 from being closed. Therefore, the operator will have to return the controller MC to the off position and reduce the speed of the vehicle to less than 55 miles per hour before power can be restored to the motors.

When the sequence drum reaches position 5 during normal acceleration or following a reapplication of power, a conductor I3'I is energized through a segment I38 on the sequence drum. The energization of the conductor I31 energizes the actuating coil of the relay AR3 through its contact members I39. The relay AR3 will close and hold itself closed through its contact members I4I which transfer the energizing circuit to the conductor 39.

The operation of the relay AR3 transfers the circuit established by the contact members of the relay SRI and the contact members I28 of the relay AR3 to the energizing circuit for the relay ARZ through contact members I42 of the relay AR3. At the same time, the conductor I26, which energizes the contact members for both relays SRI and SR2, is connected to the conductor I31 through contact members I43 of the relay AR3.

Also at this time, contact members I44 and I45 of the relay AR3 are opened to insert additional resistance in the voltage coils of the relays SRI and SR2, thereby raising the settings of both speed relays to, say, 68 miles per hour. When this speed is reached, one or both of the speed responsive relays will close their contact members to energize the relay ARZ. The operation of the relay AR2 will deenergize the actuating coil for the switch M in the manner hereinbefore explained, thereby disconnecting the motors from the power source. In order to reapply power after overspeeding, the operator must return the controller to the off position and reduce the speed to less than 55 miles per hour. Thus, it

will be seen that overspeed protection is provided for both motors.

From the foregoing description, it is apparent that we have provided a control system which aliords anti-flash protection for the motors of a vehicle by selecting the switches for establishing the proper connections for the motors when powor is reapplied at certain speeds, and preventing the reapplication of power above a predetermined speed. The present system also provides protection against overspeeding of one or more than one of the propelling motors of a vehicle.

Since numerous changes may be made in the above-described construction, and difierent embodiments of the invention may be made without departing from the spirit and thereof, it is intend that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

We claim our invention:

1. In a control system having a transformer or supplying current to a doubly-fed repulsion tarting motor, in combination, switching means for establishing the repulsion connections, additiona. switching means for establishing the doubly-fed connections, and relay means responsive to difierent speeds or the motor for selectively controlling the operation of said switch ing in accordance with the motor speed when power is reapplied to the motor.

2. In a control system having a transform r for supplying current to a doubly-f d repulsion Ul -h ditional switching means for establishing the doubly-fed connections, and means responsive to differ it amounts of armature voltage and main field crrent of the motor for selectively controlling the operation of said sv-Jitehing means when power is reapplied to the motor.

3. In a control system having a transformer upplying current to a doubly-fed repulsion I ng motor, in combination, switching means establishing the repulsion connections, adlnal switching means for estblishing the In a control system having a transformer for supplying current to a doubly-fed repulsion starting motor, in combination, switching means establishing the repulsion connections, additional switching means for establishing the doubly-fed connections, relay means responsive to different amounts of armature voltage and main field current of the motor, and auxiliary relay means cooperating with said first-named relay means to selectively control the operation of said switching means during the reapplication of power to the motor.

5. In a control system having a transformer for supplying current to a doubly-fed repulsion starting motor, in combination, swit hing means for establi hing the repulsion connections, additional switching means for establishing the doubly-fed connections, rela means responsive to different inotor speeds for selectively controlling the operation of said switching means in accordance with the motor speed when power is reapplied to the motor, and additional relay means for preventing the reapplication f power to the motor while operating above a. predetermined speed.

5. In a control system having a. transformer for supplying current to a doubly-fed repulsion starting motor, in combination, switching means for establishing the repulsion connections, additional switching means for establishing the doubly-fed connections, relay means responsive to different speeds of the motor, and auxiliary relay means cooperating with said speed-responsive relay means to prevent the reapplication of power to the motor while operating above a predetermined speed.

7. In a control system having a transformer for supplying current to a doubly-fed repulsion starting motor, in combination, switching means for establishing the repulsion connections, additional switching means for establishing the doubly-fed connections, relay means responsive to difierent speeds of the motor for selectively controlling the operation of said switching means in accordance with the motor speed when power is reapplied to the motor, a switch for disconnecting the motor from the transformer, and additional relay means for causing said switch to open when the motor exceeds a predetermined speed.

8. In a control system, the combination with a pair of doubly-fed repulsion starting motors and a power transformer for the motors, of switching means for establishing the repulsion connections, additional switching means for establishing the doubly-fed connections, and a pair of relays responsive to predetermined different speeds of the motors for selectively con trolling the operation of said switching means when power is reapplied to the motors.

9. In a control system, the combination with a pair of doubly-fed repulsion starting motors and a power transformer for the motors, of switching means for establishing the repulsion connections, additional switching means for establishing the doubly-fed connections, a pair of relays responsive to predetermined difierent speeds of the motors, and auxiliary relays cooperating with said speed-responsive relays to prevent the reapplication of power to the motors while operating above a predetermined speed.

10. In a control system, the combination with a pair of doubly-fed repulsion starting motors and a power transformer for the motors, of switching means for establishing the repulsion connections, additional switching means for establishing the doubly-fed connections, a pair of relays responsive to predetermined different speeds of the motors, and auxiliary relays cooperating with said speed-responsive relays to selectively control the operation of said switching means when power is reapplied to the motor and to prevent the reapplication of power to the motors while operating above a predetermined speed.

SIMEON E. NEWHOUSE. WILLIAM H. EUNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,157,313 Latour Oct. 19, 1915 1,236,742 Morris Aug. 14, 1917 1,251,658 Hellmund Jan. 1, 1918 1,338,367 Hellmund Apr. 27, 1920 1,386,016 Morris Aug. 2, 1921 

